Ischemic heart disease is a leading cause of death in the United States. Ischemic heart disease is a term given to heart-related conditions caused by decreased blood flow to the heart. This disease is most commonly caused by blockages in the coronary arteries, the blood vessels that provide blood to the heart. The coronary arteries most often become narrowed or blocked by a gradual build-up of atherosclerotic plaque. If the plaque significantly narrows the lumen or channel of the artery, blood flow is significantly reduced and the heart muscle does not receive the amount of blood flow necessary to meet its needs. Severe symptoms of cardiac ischemia include chest pain, heart attack, or arrhythmias.
One approach used to treat ischemic heart disease is therapeutic angiogenesis, the ability to pharmacologically induce new blood vessel growth. In therapeutic angiogenesis, new blood supplies are established for the heart to increase tissue survival and function, as well as relieve patient symptoms, such as angina. Angiogenic activity is supplied by introducing one or more of a variety of different angiogenic stimulating therapeutic agents, such as growth factors, to the heart.
The angiogenic stimulating therapeutic agents may be administered either alone or as a combination therapy with surgery or transmyocardial revascularization (TMR). In TMR, one or more small wounds are created in an ischemic heart in order to stimulate angiogenesis as part of the healing process. Delivery of angiogenic stimulating therapeutic agents to the wound sites allows for enhanced angiogenesis. Conventionally, a laser is used to create the small wounds in the heart tissue. Once the wounds are created, the therapeutic agents are introduced using a syringe.
While current therapeutic angiogenesis and TMR techniques are adequate, they are subject to improvement. Specifically, there is a need for an improved device and method for creating small wounds in the heart. Further, there is a need for an improved device and method for delivering therapeutic agents to the wounds.